Device for relieving pressure in boilers



(No Model.) 2 Sheets- Sheet 1.-

J. G.J.DA71S.

DEVICE FOR RELIEVING PRESSURE IN BOILERS.

No. 579,700. Patented Mar. so, 1897.

nHif @ses M i Y Jimmy (No Model.) 2 sheets-sheet 2.

J. GQJ. DAVIS'. DEVICE FOR EELIEVING PRESSURE IN BOILERS.

170.579,700. Patented Mar. 30, 1897. l

:llllhlllllli ilnrrn STATES JOHN GADDY JONES DAVIS, OF AUGUSTA, GEORGIA.

DEVIC-E FOR RELIEVING PRESSURE IN BOILERS.

SPECIFICATION forming part of Letters Patent No. 579,700, dated March 30, 1897. Application filed J'une 9, 1896. Serial No. 594,881. (No model.)

To all whom it may concern:

Be it known that I, JOHN GADDY JoNEs DAVIS, a resident of Augusta, in the county of Richmond and State of Georgia, have invented certain new and useful Improvements in Devices for Relieving Pressure in Boilers, dre.; and I do hereby declare the following Y to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. v

My invention relates to an improvement in devices for relieving pressure in boilers, radiators, &c., the objects of the invention being to so construct a system of devices that when pressure in a steam-boiler or other apparatus to which the devices are attached rises beyond a predetermined degree such pressure will be automatically relieved and the escaping steam utilized for operating devices for sounding a whistle, ringing a bell, and reducing the re under the apparatus in which the steam is generated.

Vith these objects in view the invention consists in certain novel features of construction and combinations and arrangements of parts, as hereinafter set forth, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a side view of my improved valve mechanism. Fig. 2 is a sectional view. Fig. 3 is a plan view of one set of electrical contact devices. Fig. 4 is a vertical cross-section. Fig. 5 is a detail view of one of the auxiliary exhaustvalve and tripping mechanisms. Fig. 6 is a view showing the arrangement of the vario us devices when assembled. i

A indicates a valve-casing having a hollowr screw-threaded shank 1 for attachment to a boiler 54, and an exhaust-port 2, which communicates with a screw-threaded nipple 3 on the valve-casing. The upper portion of the valve-casing is made with two pairs of arms 4 5, and the arms 4 are provided with elongated openings 6, in which a knife-edge 42 has its bearing, said knife-edge being secured to a cylindrical pin 41 and constituting trunnions fora scale-beam 20 through an opening 27, in which latter the cylindrical pin 41 passes.

Between the pairs of arms 4 5 a laterallyprojecting arm 8 is secured and provided at its free end with a holder 11 for the reception of plates 12 13 of insulating material, between which plates contact arms or springs 18 19 are secured, the rear ends 16 17 of said arms or plates being adapted for the attachment of electric wires. The outer end of the scalebeam 20 is made with an upwardly and rearwardly projecting arm Z) for the reception of a holder c, in which plates CZ cl of insulating material are located. Between the plates d d contact-plates are secured, so as to be engaged by the contact-arms 1S 19 to close electric circuits, for a purpose hereinafter explained.

The scale-beam is provided with graduations designating steam-pressure in pounds, and the upper edge of the long arm of said beam is made with notches for the reception of a knife-edge pin 23, secured in an adjustable weight 21, and serving as a support for the latter on the scale-beam. The weight 21 is made with a screw-threaded socket for the reception of a screw 24, adapted to engage the lower edge of the scale-beam and prevent accidental displacement of the weight. A weight 25 is mounted on the small arm of the beam 2O and held in position by means of a screw 26.

Between the pairs of arms 4 5 at the upper end of the valve-casing A a stirrup 35 is loosely disposed and adapted to loosely'embrace the xed end of the arm 8, by which it will be guided. 1 The vertical arms of the stirrup 35 are made with elongated slots 3S, in which a knife-edge a has its bearings, said knife-edge being carried by a cylindrical pin 40, which passes through a hole 2S in an enlargement fon the scale-beam. A screw 29 passes into the enlargement f and provided with an annular groove 30 for the reception of the knife-edge 42, and with an annular groove 31 for the reception of the knife-edge a. By means of the screw 29 the knife-edges 42 and CL can be moved slightly (the pins 40 41 turning in their bearings in the scale-beam 20) when they become slightly rounded, so as to insure the maintenance of sharp bearing edges.

Lateral displacement of the scale-beam will be prevented by means of caps g, secured to the arms 4 and the stirrup 35.

IOO

The stirrup 35 is made with a shank which l depends within the valve-casing and provided with a conical lower end 36, adapted to pass through a similarly-shaped opening in a block 33, secured within the casing A by means of pins 3l. The shank of the stirrup 35 is made with a longitudinal screwthreaded opening for the reception of a screw 37, the lower pointed end of which projects below the conical end of the stirrup-shanlc. The lower portion of the valve-casing forms a cylindrical valvechamber 7L, in which a piston-valve 32 is located and held normally to its seat yL' by the screw 37 in the stirrup 35. The upward movement will be limited by the block The valve has a neat it within the valve-chamber and prevents the escape of steam up through the valvescasin g to the bearings of the scalewbeam. The valve 32 normally closes the exhaust-duct 2 and also the passage through the shank l and presents a dat surface to the steam-pressure entering said shank l.

From the construction and arrangement of parts above described it will be readily seen that when the pressure of steam in the boiler 54 rises beyond a predetermined degree (at which the weight 2l is set on the scale-beam 20) the piston-valve 32 will rise and open the exhaust-port 2, thus permitting the escape of steam through a pipe G4, connected with the nipple 3. When the valve is thus raised by the excessive steam-pressure, the stirrup 35 will be raised, resulting in raising the long arm of the scale-beam and causing the coutact-plates d to engage the contact-arms 18 19. An electric rheotome-bell ,7' is included in circuit with one of the contact-plates (I, the contact-arm 19, and a suitable battery 7c, so that when the scale-beam is raised in the manner above described an electric circuit through said bell will be closed and the bell sounded, thus indicating that an excessive pressure of steam exists in the boiler.

A valve mechanism B, substantially identical with that above described, is connected with the boiler 5l. In lieu of the arm S above described the valve mechanism B is provided with an L-shaped arm Z, secured to the arms 4 5 of the valve-casing A, the short depending arm 50 of said L-shaped arm terminating in proximity to the free end of the long arm of the scale-beam m, as clearl y shown Iin Fig. 5. A lever 51 is pivoted at the free end of arm 50 and provided with a shoulder n to be engaged by a pin 52 at the free end of the scale-beam, so as to force the free end of said lever 51 in engagement with a shoulder 40 on a pivoted lever 48, and the free end of the latter is adapted to engage a shoulder 47 of a pivotcd armaturedever 4G. The normal engagement of the armature-lever 4G and lever 48 is insured by a sp1-ing o. The levers 4G, LIS, and 5l thus serve to lock the scale-beam m and consequently the valve mechanism B, and said levers will be released so as to permit the valve mechanism B to operate by means of an electromagnet 45, adapted to actuate the armature-lever, the

coil of said electromagnet being included in circuit with a battery p, one of the contactplates d, and the contact-arm 18, which circuit also includes an electromagnet q, adapted to actuate tripping mechanism identical with that above described, Afor a valve mechanism C identical with the valve mechanism A and B. The easing ot' the valve mechanism C communicates with the boiler in proximity to the water-line, so that when the valve rises excessive steam and watercan escape through a pipe G3, connected with the nipple The valve mechanism B may connect with the boiler 5l at a point in proximity to the valve mechanism A, and with the nipple il of said valve mechanism B two pipes (5l and 05 communicate, the pipe (i5 leading to a steamwhistle 5G and the pipe (5l leading to a receptacle 5f), containing a chemical compound which will be driven by the steam through a pipe G0 into the lire in the furnace 53 and rcsult in reducing the tire.

Assuming that the main-valve mechanism is set to operate when the pressure in the boiler exceeds one hundred and fifty pounds and the auxiliary valves are set to operate at one hundred and twenty-f`1ve pounds pressure, under such conditions when the pressure exceeds one hundred and 'fifty pounds the piston-valve of the main-valve mechanism will rise and cause the free end of the long arm of scale-beam 2O to rise and close the electrical circuits through the bell and the electromagnets of the valve mechanisms B and C, whereupon said magnets will act to release the trip mechanisms and permit the valves of the mechanisms I3 and C to open and allow excessive steam and water to exhaust from valve mechanism C and steam to exhaust from valve mechanism B for the pu rpose of sounding the whistle from the receptacle 59 to the lire in the furnace.

From the contruction and arrangement of parts above .described it will be seen that when the steam-pressure in the boiler becomes excessive the main-valve mechanism A will operate to exhaust a portion of the steam, ring a bell, cause other valves to be opened for exhausting excessive steam. and water, sounding a whistle, and injecting a chemical into the furnace for subduing or reducing the lire.

Then the pressure in the boiler drops below one hundred and twenty-tive pounds, the valves will be automatically reset and the trip devices of valve mechanisms l5 and C can then be normally reset.

Various slight changes might be made in the details of my invention without departing from the spirit thereof or limiting its scope, and hence I do not wish to limit myself to the precise details herein set fori h; but,

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The combination with a safety-valve of an electric bell, and electric contacts con- IOO IIO

nected with the scale-beam, of the safetyvalve and an arm connected therewith for automatically closing the circuit, when the valve opens to exhaust steam, and thereby cause the bell to operate, substantially as set forth.

2. The combination with a steam-boiler, of a safety valve and one or more auxiliary valves, signaling devices adapted to be operated by the opening of the safety-valve and auxiliary val-ves and an electric circuit and electrically-operated devices, for automatically ringing a bell, and unlocking the auxiliary valves, substantially as set forth.

3. The combination with a steam-boiler and a receptacle for containing a chemical, a furnace, of valve mechanism adapted to permit the exhaust of steam when the pressure becomes excessive and connections between the chemical-receptacle and the valve mechanism and furnace, whereby the exhaust-steam will be utilized to inject a chemical into the iire in the furnace, substantially as set forth.

4. The combination with a steam-boiler, of a main safety-valve mechanism adapted to permit the escape of steam when the pressure in the boiler becomes excessive, and an auxiliary-valve mechanismconnected with the boiler in proximity to the water-line and adapt-ed to be released by the operation of the main safety-valve mechanism, substantially as set forth.

5. The combination with asteam-boiler, of a main safety-valve mechanism comm unicating therewith, auxiliary-valve mechanisms communicating with said boiler, electromagnet trip devices adapted to normally lock said auxiliary-valve mechanisms, a circuit-closer connected with and operated by the main safety-valve mechanism and an electric circuitincluding the electromagnets of the trip devices of the auxiliary-valve mechanisms, and said circuit-closer, substantially as set forth.

G. The combination with a safety valve casing, a scale-beam pivoted thereto, a valve, a stirrup resting upon the valve and retaining it against its seat, and serving as a pivotal support for the scale-beam, substantially as set forth.

7. The combination with a valve-Casin g and a scale-beam connected thereto, of a pistonvalve in said casing, and an adjustable connection between said valve and scale-beam at one side of the pivotal connection of the latter with the valve-casing, substantially as set forth.

8. The combination with a valve-'casing and a scale-beam pivotally connected therewith, of a piston-valve in said casing, a stirrup connected with the scale-beam to one side of the connection of the latter with the Valve-Casin g, and a screw passingr through said stirrup and adapted to normally bear on said piston-valve, substantially as set forth.

' 9. Thecombination withavalVe-casingand a scale-beam pivotally connected therewith7 of a piston-Valve in said casing, a block having tapering opening in said casing above the valve, and a stirrup connected to the scalebeam and having a'tapering lower end to project through the tapering opening` in said block and normally engage the piston-valve, substantially as set forth.

10. The combination with a valve-casing, of a piston-valve therein, a scale-beam, a cylindrical pin passing through the scale-beam and carrying knife-edges having a bearing in the valve-casing, a stirrup adapted to bear on the piston-Valve, a cylindrical pin passing through the scale-beam and carrying 'knifeedges having bearings in the stirrup, and a screw in the scale-beam adapted to engage said knife-edges for adjusting them, substantially as set forth.

l1. The combination with a valve-casing having two pairs of arms and a piston-valve in said casing, of a scale-beam pivotally connected to one pair of arms, a stirrup located between the pairs of arms and adapted to bear against the piston-Valve, said stirrup being pivotally connected to the scale-beam, a rigid arm secured to said pairs of arms, insulated contact-plates secured to said rigid arm, insulated contact-plates secured to the scale-beam, and electric circuits including said contactplates and signal and releasing devices, substantially as set forth.

12. The combination with a casing and a piston-valve therein of a scale-beam pivotally connected with the casing, a stirrup connected with the scale-beam and bearing on said piston-valve, a weight on each arm of said scalebeam, and screws passing through said weights and engaging the scale-beam, substantially as set forth.

13. The combination with a steam-boiler and its furnace, of a safety-valve and an auxiliary valve, a receptacle for chemicals, and a pipe, leading from the chemical-receptacle to the furnace, whereby on the opening of the auxiliary valve, steam will be forced through the chemical-receptacle and force the chemicals into the furnace, substantially as set forth.

14E. The combination with a steam-boiler .0f a safety-valve, an auxiliary Valve, and a steam-whistle connected with the auxiliary valve, of electric circuits and electrically-actuated mechanism included therein, whereby on the opening of the safety-valve, the auxiliary valve will be released with the result that the whistle will be operated, substantially as set forth.

15. The combination with a steam-boiler and its furnace, a safety-valve, and auxiliary valves, of a steam-whistle, an electrically-actuated bell, a chemical-receptacle, and electric circuits and electrically-actuated devices included therein, substantially as set forth. 16. The combination with a steam-boiler, of a sensitive valve blown by excessive steampressure and adapted to complete an electrical circuit when blown, an electromagnet included in said electrical circuit, and trip mechanism released by the action of the mag- IOO IIO

net and adapted to open the second valve, substantially as described.

17. The combination with a steam-boiler, of a valve blown by excessive steam-pressure and comprising a pivoted scale-beam, a piston directly operated on by the steani, and a stirrup straddling the scale-beam and pivoted thereto and provided with a pointed shank bearing on the pistou, substantially as de scribed.

18. The combination with a steam-boiler, of a valve blown by excessive steam-pressure, and comprising a pivoted scale-beam, a piston directly acted on by the steam-pressure and governing an exhaust-port, a stirrup straddling the scale-beam, being pivoted thereto and provided with a shank, andan adjustingscrew in said shank and having its end bearing on the piston, substantially as described.

19. The combination with a steam-boiler, of a valve blown by excessive steam-pressure and comprising a valve-casing, a scale-beam hung on an adjustable knife-edge, a stirrup straddling the scale-beam and hung on an adjustable knife-edge, said stirrup being provided with a pointed shank, and a piston on which the pointed shank rests, substantially as described.

20. The combination with a steam-boiler, oi' a scale-beann having an adjustable Weight and carrying an electrical contact device, a contact'arin carrying an electrical contact device, and a valve 'for raising the scalebean1 to bring said Contact devices into connection, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribin g witnesses.

JOHN GADDY JONES DAVIS.

Witnesses:

JOHN L. ARMSTRONG, J As. P. ARMSTRONG. 

